Proximal tortuosity of the vasculature is problematic for all medical catheter devices such as atherectomy devices, angioplasty devices, stent delivery devices, and filter delivery devices. Wire guides are therefore typically used to navigate the vasculature of a patient during percutaneous interventional procedures. Once the wire guide has been introduced, it may then be used to introduce one or more medical catheter devices. Thus, most wire guides are typically 0.014 inches in diameter and have a lubricious coating to enhance wire guide introduction movement. Conventional 0.014 inch floppy wire guides must have sufficient flexibility and torque control for navigation through tortuous vessels. At the same time, the wire guide must have a certain amount of rigidity to pass through lesions, straighten extremely tortuous vessels, and support medical catheter devices that are introduced over the wire guide.
Accordingly, wire guides are subjected to potentially conflicting requirements. Conventional 0.014 inch floppy wire guides are usually sufficient for navigation of moderately tortuous vessels. However, in some situations the wire guide tip may prolapse away from the site to which it is guiding the device. For example, balloon angioplasty in vessels with proximal tortuosity has been associated with a higher incidence of acute complications and procedural failure due to the inability to cross lesions with a conventional floppy wire guide, and due to the inability of the wire guide to provide adequate support to the balloon catheter. Heavy-duty wire guides, on the other hand, are generally not well suited as primary wire guides because of their stiffness and potential for causing injury to the vessel during introduction.
It may therefore be desirable to use conventional floppy wire guides for navigation of tortuous vessels, and then enhance the conventional wire guide with a supplemental wire guide. The supplemental wire guide will straighten out the vessel curves and ease further wire guide movement. Additionally, the supplemental wire guide provides greater support and enhances the tracking of balloons, stents, stent delivery devices, atherectomy devices, and other medical catheter devices as compared to a conventional floppy wire guide. This technique is commonly referred to as the “Buddy Wire” technique, details of which are disclosed in U.S. patent application Ser. No. 11/081,146, filed Mar. 16, 2005.
The applicant has discovered that it can become difficult to distinguish between the previously introduced wire guide and the supplemental wire guide (or guides), especially once the supplemental wire guide is fully advanced and positioned similarly or adjacent to the previously introduced wire guide. That is, the proximal end of these wire guides, which remains outside of the vasculature and accessible to the physician, can become confused. Multiple exchanges of wire guides during interventional procedures may further complicate wire guide identification.
Accordingly, there exists a need to provide a wire guide for intracorporeal procedures that may be easily and reliably distinguished from other introduced wire guides.